Heat duplicating products and process



y 1966 M. SHARKEY 3,252,413

HEAT DUPLIGATING PRODUCTS AND PROCESS 1 "Med Jul; 1964 FLEXiBLE FOUNDATION w 1\\\\Y W12 TRANSFER LAYER 5 ?Q-/0 mAsTEia EHEET INVENTOR.

Me Zvin fi/mrkey BY W M k-QiM! HTTOA NEXS United States Patent 3,252,413 HEAT DUPLICATING PRODUCTS AND PROCESS Melvin Sharkey, 1614 Hereford Road, Hewlett, N.Y. Filed July 22, 1964, Ser. No. 384,409 11 Claims. (Cl. 101149.4)

The present invention relates to novel dry hectograph duplicating master sheets, transfer elements for the imaging thereof and to the process of duplicating therewith by means of heat and in the absence of volatile solvents.

In the conventional spirit hectograph duplicating process, dye images are typed or drawnonto a master sheet and these images are duplicated onto copy sheets which have been wetted with volatile dye solvent such as ethanol, the solvent dissolving dye from the images onto the copy sheet prior to its evaporation.

While the spirit process enjoys widespread commerical success, it has at least one great disadvantage which prohibits its use for certain applications such as for the production of copies of patterns used in the garment industry. The spirits used in the spirit duplicating process are very volatile and combustible and therefore present a fire and explosion hazard which prevents their use in areas where prohibited by fire laws.

A number of dry hetcograph processes have been proposed in an effort to eliminate the necessity of using volatile spirits. Most of these methods employ nonvolatile dye-solvent coatings on the copy sheets so that when master images are pressed thereagainst, portions of the master images are transferred to the copy sheet coating and gradually dissolved therein. Such a process, as taught by US. Patent No. 3,034,428, has the disadvantages that dissolution and development of the dye color on the copy sheet is slow and uncontrollable since a mass of dye is pressure-transferred to the copy sheet and the copy sheet coating continues to dissolve the dye into areas adjacent to the areas which actually support the dye images so that broadening and blurring of the images results.

However, equally objectionable is the fact that the specially-coated copy sheets are relatively expensive and this expense, when added to the expense of providing conventional master paper which is also costly, makes the process prohibitive for a large scale web-copy operation as is used in the pattern-copying field.

A dry hectograph copy process has been proposed in US. Patent No. 2,501,495 which employs conventional copy paper. According to this process, dye images are typed upon the resinous release coating on .a master sheet and the images are then pressed against a copy sheet while the master is cooled and the copy sheet is heated. This process is rather tedious due to the necessity of closely controlling the temperature of a cooling roll and a heating roll in close proximity, but more importantly this process is not a dye-dissolving process but depends upon the mass transfer of portions of the master images to each copy sheet. Undissolved hectograph dyestuff is so easily smudged and has such a tremendous staining power that the copies imaged by this process cannot be handled without blurring the images and staining the hands and clothing. This makes such copies useless in the pattern field where staining of the fabric being cut cannot be tolerated.

With these problems and disadvantages of the prior art in mind, it is an object of the present invention to provide novel hectograph composition images on master sheets which can be dissolved onto conventional copy papers without the use of volatile spirits and without the necessity and expense of using specially-coated master sheets and copy sheets.

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It is another object of this invention to provide a novel dry hectograph copying process which eliminates the necessity for using especially-coated copy sheets and master sheets and volatile organic solvents and which operates by means of heat.

It is another object of this invention to provide imaged hectograph master sheets which are dry-to-the-touch but which are activated by means of heat to provide suflicient non-volatile dye solvent to dissolve the dyestuff in the master images so that it can be transferred in developed, dissolved form to a copy sheet in intimate contact therewith.

It is still another object of the invention to provide imaged hectograph master sheets which can be used periodically for the production of duplicate copies by means of heat alone and which revert to dry stable form upon cooling after each use.

These and other objects and advantages are accomplished according to this invention in a manner which will be clear to those skilled in the art in the light of the present disclosure including the drawings, in which:

FIGURE 1 is a diagrammatic cross-section, to an enlarged scale, of a master sheet carrying images consisting of the novel hectograph composition of the present invention and suitable for use as a master sheet in the present dry copying process.

FIGURE 2 is a sectional view showing an arrangement of a master-carrying drum, a master sheet heating system and a pressure roll included in an appaartus suitable for carrying out the process used herein for duplicating and transferring hectograph images from a master sheet to successive copy sheets.

FIG. 3 is a sectional view of an arrangement of a continuous master sheet and a continuous copy sheet, as used in the pattern-making art.

The objects and advantages of the present invention are accomplished by the discovery of a novel hectograph duplicating composition which contains a large amount of undissolved hectograph dyestuff and also includes a large amount of a solid heat-meltable material which, in its heat-melted state, is a good solvent for the hectograph dyestuff. I have discovered that hectograph compositions of this type having a self-contained heat-activatable dye solvent may be used to form images on any flexible sheet, which images may be duplicated a great number of times on a succession of untreated copy sheets or onto a continuous copy web by applying heat to the images to melt the solid dye solvent which dissolves the dyestuffs and permits it to stain and thereby image the copy sheet or web pressed thereagainst.

According to the preferred embodiment of the invention, the hectograph composition includes a binder material such as wax or a film-forming binder material such as a cellulose plastic or a synthetic thermoplastic resin and is coated onto a flexible foundation sheet or ribbon 11 by conventional hot melt or solvent coating techniques to form a pressure-transferable imaging layer 12 thereon as shown in FIG. l. This transfer sheet has the appearance of a conventional hectograph transfer sheet and, if desired, may also carry a supercoating including lamelliform particles, resins or other agents lending cleanliness or transferahility thereto in conventional manner.

The novel hectograph compositions of the present invention include a solid. particulate undissolved conventional hectograph dyestufi, which is preferably a triphenylmethane dye such as crystal violet or methyl violet, and a solid material which is meltablc at temperatures ranging from about F. to about 250 F. and preferably from F. to about F. and which is a solvent in its melted liquid state for the particular dyestuff used therewith. Preferred solvent materials include the fatty 3 acids such as stearic, palmitic, lauric and capric; fatty alcohols such as cetyl, myristyl and stearyl; solid esters of various glycols and organic acids; and solid glycol ethers such as polyethyleneand polypropylene-glycol ethers.

The present hectograph transfer sheets are preferably prepared by solvent-coating techniques to avoid the necessity of heating the composition during the coating opera tion thereby avoiding the possibility of predissolving any of the hectograph dyestutf. According to this embodimerit, a film-forming binder material such as ethyl cellulose or polyvinyl acetate is preferably used as th binder material for the hectograph dyestuff and the solid dye solvent, and a volatile organic solvent is used to dissolve the binder material and the solid dye solvent to reduce the composition to a coatable consistency. The volatile organic solvent must be one which does not dissolve the dyestuff. The solution including the dispersed particulate dyestull is coated onto a flexible foundation sheet such as paper or plastic film and the solvent is evaporated to form a frangible transfer layer. present dye solvents are relatively solid waxy materials as opposed to semi-solids at room temperatures, they may serve as the SOle binding agents, if desired.

The present transfer sheets may also be prepared by conventional hot melt techniques using wax binder material, if desired, or merely using the solid dye solvent as the sole binding agent. While it is perferred to avoid the use of elevated temperatures during the coating of the hectograph composition onto the foundation, it has been found that such elevated temperatures do not interfere substantially with the ability of the composition to form a great many duplicate copies since as many as one hundred or more clean sharp copies can be run from images produced with hot melt composition. It is difiicult to understand why heat does not have a more adverse effect in the coating step but it appears that the solid dye solvents have a limited dissolving ability so that only a small portion of dyestutf appears to be dissolved during the coating operation. When the composition is transferred in the form of images 13 to a flexible sheet or master 10. as shown by FIG. l, and heat is applied during the duplicating process, new dycstutf appears to be continuously dissolved into the dye solvent as the previously dissolved dyestutf is leached out of the composition onto the copy sheets. The binder material remains substantially completely behind on the master sheet and the duplicate images formed on the copy sheets consist substantially completely of dissolved dyestuff and a small amount of solid dye solvent as evidenced by the cleanliness and smudge-resistance of the duplicate images.

If desired, the imaged master sheet may be heated before it is contacted with the copy sheet, provided that contact is made while the dye-solvent in the images is still in the melted state. Also, in cases where it is desired to use infrared radiation as the heating means, it is preferred that the master paper he pigmented dark so that it will absorb the infrared radiation and convert it to heat, or that the hectograph dyestuff or other ingredients of the images absorb infrared radiation.

Any suitable apparatus may be used for the present duplicating process provided that it includes heating means to heat the master images between 80 F. and 250 F. to melt the dye solvent in the images, and pressure means to force the heated master into intimate surface contact with the copy sheet.

The device illustrated by FIG. 2 comprises a heated drum having mounted thereon the imaged master sheet 10 and a pressure roller urged against the heated drum. Drum 20 is internally heated by means of electrical heating means 21 to provide a temperature at the surface of the drum sufiiciently high to melt the dye solvent. If desired, external heating means such as infrared radiation lamp 22 may be used as a supplement to or in place of the internal heating means 21. Copies are made by urg ing a copy sheet 15 between the drum and the pressure Since some of the roller whereby the dissolved dyestuff in the master images 13 stains the surface of the copy sheet to form duplicate imagcs .14 thereon, as shown in FIG. 3. These duplicate images have an instant color since they consist of dissolved dyestuff, and they are substantially non-smearing and clcan-to-the-touch since they are substantially free of undissolved dyestutf and wax or other binder material.

The embodiment illustrated by FIG. 3 of the drawing pertains to continuous web copying whereby a continuous imaged master sheet 10 from supply roll 41 and a continuuus copy sheet 15 from supply roll 51 are urged into pressure contact between roller 25 and pressure roller 30 to effect the duplicating step after which the master sheet is wound on take-up roll 42 and the imaged copy sheet carrying dye images 14 is Wound on take-up roll 52. The heating of the master sheet prior to contact with the copy sheet is accomplished by infrared radiation lamps 22 and, if desired, by internal heating means in roller 25.

It is a preferred embodiment of the present invention that the binder material for the hectograph dyestuff in images 13 on the master sheet, if they contain any binder material, be non-meltable at the temperature used to effect the present duplicating process since melting of the binder material sometimes permits a melting-over or mass transfer of wax, plastic or rcsin binder to the copy sheet if heavy pressure is used so that the images formed thereon contain solid binder material and undissolved dyestutf and would be easily smudged and dirty-to-thedouch.

The following examples are illustrative of compositions coming within the present invention:

Example 1 Ingredients: Parts by weight Ethyl cellulose 5 Cetyl alcohol 15 Stearic acid 10 Crystal violet 20 Toluol 50 The composition was mixed thoroughly at room temperature and applied to a paper web as a uniform coating. After evaporation of the toluol, there results a thin frangible layer which is entirely transferable including the ethyl cellulose under the effects of imaging pressure.

A master sheet, reverse-imaged with the above cornposition as shown by FIG. 1, may be duplicated several hundred times by either of the arrangements illustrated by FIGS. 2 and 3 of the drawing whereby the master images are heated and pressed into intimate surface contact with a succession of copy sheets or with a continuous copy sheet. With compositions of this type, including ethyl cellulose or other high melting point film-forming binder materials, the amount of heat applied to the master images is not critical and temperatures anywhere within the range of F. to 250 F. may be used provided that they are sufliicently high to melt the solid dye solvent.

Example 2 Ingredients:

Parts by weight Carnauba Wax The above ingredients were melted together at a temperature of 180 F. and spread as a thin layer on a paper foundation to form a transfer sheet. A master sheet imaged with this compoistion may be duplicated one hundred or more times in the same manner as the composition of Example 1 with the exception that the temperature of the duplicating process should be maintained below 180 F. and in the area of the melting temperature of cetyl alcohol or at about F. to P. so that the wax binder material remains solid and non-transferable while the cetyl alcohol melts and dissolves the dyestutf.

Example 3 Ingredients: Parts by weight Lanette wax 6 Methyl violet 40 The above ingredients are applied as a thin pressuretransferable layer to a film foundation sheet either by heating to a temperature of 130 F. and using the hot melt technique or by dissolving the lanette wax in 50 parts by weight of toluol and using the solvent coating technique. A master sheet imaged with the above composition may be duplicated several hundred times in the same manner as the composition of Example 1 using a duplicating temperature above about 122 P. which is the melting temperature of lanette wax. Lanette wax is a mixture of fatty alcohols, mainly stearyl alcohol.

It has been found preferable that the hectograph compositions of the present invention contain at least about 30% by weight and up to about 70% by weight of the solid undissolved dyestuif based upon the total dry weight of the composition.

The amount of solid dye solvent present in the present hectograph compositions may be varied greatly depending upon the amount of dyestutf present and the copying power or length of run desired. In general, it is preferred that the dye solvent be present in an amount equal to or exceeding the amount of dyestuff present. Thus the dye solvent generally is present in an amount equalling at least about 30% by weight of the total composition.

It is preferred that a separate binder material be present, such as wax or resin, and this material is generally present in an amount ranging from about 5% to about 40% by weight of the total composition.

While the present process has been defined and illustrated mainly from the point of View of applying heat or infrared radiation to the master sheet or directly to the master images, it should be understood that the invention encompasses any means whereby melting of the dye solvent in the master images is brought about. For instance heat may be applied to the copy sheet so that pressing of the heated copy sheet against the master images causes melting of the dye solvent. If desired, the copy sheet may be one which is coated on the back with an infrared radiation-absorbing layer so that the application of infrared radiation thereto causes heating of the copy sheet. Also it is possible to carry out the present process in a heated atmosphere such as in an oven or the like whereby the copy sheet, master sheet and master images are all heated to the same extent.

Variations and modifications may be made within the scope of the claims and portions of the improvements may be used without others.

I claim:

1. A novel hectograph master sheet suitable for duplication by means of heat and in the absence of volatile organic solvents comprising a flexible foundation having thereon images consisting of at least about 30% by weight of a solid undissolved hectograph dyestuff and at least about 30% by weight of a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestulf.

2. A novel hectograph master sheet suitable for duplication by means of heat and in the absence of volatile organic solvents comprising a flexible foundation having thereon pressure-applied images comprising from about 0% to about 40% by weight of a binder material, from about 30% to about 70% by weight of a solid undissolved hectograph dyestuff and at least about 30% by weight of a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestufi.

3. A novel dry hectograph duplicating process comprising the steps of (a) superposing a master sheet with a transfer sheet carrying a layer of pressure-transferable composition comprising solid undissolved hectograph dyestuff and a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff;

(b) applying imaging pressure against the superposed sheets to cause portions of the transfer layer to transfer substantially completely to the surface of the master sheet in the form of images;

(0) heating said images to melt at least a portion of said heat-meltable material and cause it to dissolve at least a portion of said solid dyestuff; and

(d) pressing said heated images against a copy sheet whereby substantially only the dyestuff dissolved in the heat-melted dye solvent transfers to and stains the surface of the copy sheet to form smudge-resistant dissolved dyestuff images thereon in areas corresponding to the imaged areas of the master sheet.

4. The process according to claim 3 in which heating of the images is effected while the images are in pressure contact with the copy sheet.

, 5. A novel dry hectograph duplicating process comprising the steps of (a) superposing a master sheet with a transfer sheet carrying a layer of pressure-transferable composition comprising solid undissolved hectograph dyestuff and a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff and which is at least one material selected from the group consisting of fatty acids, fatty alcohols, solid esters and solid ethers having a melting point within the range of from about F. to about 250 F.;

(b) applying imaging pressure against the superposed sheets to cause portions of the transfer layer to transfer substantially completely to the surface of the master sheet in the form of images;

(c) heating said images to a temperature of from about 80 F. to about 250 F. to melt at least a portion of said heat-meltable material and cause it to dissolve at least a portion of said solid dyestutf; and

(d) pressing said'heated images against a copy sheet whereby substantially only the dyestuff dissolved in the heat-melted dye solvent transfers to and stains the surface of the copy sheet to form smudge-resistant dissolved dyestuff images thereon in areas corresponding to the imaged areas of the master sheet.

6. A novel dry hectograph duplicating process com prising the steps of i (a) superposing a master sheet with a transfer sheet carrying a layer of pressure-transferable composition comprising at least about 30% by weight of a solid undissolved hectograph dyestuff and at least about 30% by weight of a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff;

(b) applying imaging pressure against the superposed sheets to cause portions of the transfer layer to transfer substantially completely to the surface of the master sheet in the form of images;

(c) heating said images to melt at least a portion of said heat-meltable material and cause it to dissolve at least a portion of said solid dyestulf; and

(d) pressing said heated images against a copy sheet whereby substantially only the dyestulf dissolved in the heat-melted dye solvent transfers to and stains the surface of the copy sheet to form smudge-resistant dissolved dyestulf images thereon in areas corresponding to the imaged areas of the master sheet.

7. A novel dry hectograph duplicating process comprising the steps of (a) superposing a master sheet with a transfer sheet carrying a layer of pressure-transferable composition comprising solid undissolved hectograph dyestufi, infrared absorbent material and a solid heatmeltable material which, in its heat-melted state, is a solvent for the said dyestutf;

(b) applying imaging pressure against the superposed sheets to cause portions of the transfer layer to transfer substantially completely to the surface of the master sheet in the form of images;

(c) applying infrared radiation to said images to melt at least a portion of said heat-meltable material and cause it to dissolve at least a portion of said solid dyestufi; and

(d) pressing said heated images against a copy sheet whereby substantially only the dyestuft' dissolved in the heat-melted dye solvent transfers to and stains the surface of the copy sheet to form smudge-resistant dissolved dyestutf images thereon in areas corresponding to the imaged areas of the master sheet.

8. A novel dry hectograph duplicating process comprising the steps of (a) applying to the surface of a master sheet images comprising a solid binder material, solid undissolved hectograph dyestuff and a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff;

(b) heating said images to a temperature sufficiently high to melt said heat-meltable material but not sufficiently high to melt said solid binder, whereby at least a portion of said solid dyestufi' is dissolved in said heat-melted material; and

(c) pressing said heated images against a copy sheet whereby the dissolved dyestuff stains the surface of the copy sheet to form dissolved dyestufl images thereon in areas corresponding to the imaged areas of the master sheet.

9. A novel dry hectograph duplicating process comprising the steps of (a) applying to the surface of a master sheet images comprising at least about by weight of a solid binder material, at least about by weight of a solid undissolved hectograph dyestuff and at least about 30% by weight of a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff;

(b) heating said images to a temperature sufliciently high to melt said heat-meltable material but not sufficiently high to melt said solid binder, whereby at least a portion of said solid dyestuff is dissolved in said heat-melted material; and

(c) pressing said heated images against a copy sheet whereby the dissolved dyestulf stains the surface of the copy sheet to form dissolved dyestulf images thereon in areas corresponding to the imaged areas of the master sheet.

10. A novel dry hectograph duplicating process comprising the steps of (a) applying to the surface of a master sheet images comprising from about 0% to about 40% by Weight of a solid binder material, from about 30% to about by weight of a solid undissolved hectograph dyestuff and at least about 30% by weight of a solid heat-meltable material which, in its heat-melted state, is a solvent for the said dyestuff;

(b) heating said images to a temperature sufiiciently high to melt said beat-meltable material but not sufficiently high to melt said solid binder, whereby at least a portion of said solid dyestuff is dissolved in said heat-melted material; and

(c) pressing said heated images against a copy sheet whereby the dissolved dyestuff stains the surface of the copy sheet to form dissolved dyestuff images thereon in areas corresponding to the imaged areas of the master sheet.

11. A novel dry hectograph duplicating process comprising the steps of (a) applying to the surface of a master sheet images consisting of solid undissolved hectograph dyestuff and a solid heat-meltable material which, in its heatmelted state, is a solvent for the said dyestuff; and (b) heating said images to melt at least a portion of said heat-meltable material and cause it to dissolve at least a portion of said solid dyestuff and pressing said images against a heated copy sheet, whereby the dissolved dyestuff stains the surface of the copy sheet to form dissolved clyestulf images thereon in areas corresponding to the imaged areas of the master sheet.

References Cited by the Examiner UNITED STATES PATENTS 1,925,235 9/1933 Dixon 11736.1 1,978,790 10/1934 Gould et al. 101-427 2,320,769 6/1943 Champion 101-149.4 2,489,229 11/1949 Steckley 10127 2,501,495 3/1950 Carroll et a1. 101149.4 2,616,961 11/1952 Groak 101-1494 X 2,936,247 5/1960 Francis et a1. 11736.1 3,088,028 4/19 63 Newman l0l149.5 X 3,119,014 1/1964 Newman 117--36.1 X 3,148,617 9/1964 Roshkind 101149.4

ROBERT E. PULFREY, Primary Examiner.

DAVID KLEIN, Examiner.

JANYCE A. BELL, Assistant Examiner. 

10. A NOVEL DRY HECTOGRAPH DUPLICATING PROCESS COMPRISING THE STEPS OF (A) APPLYING TO THE SURFACE OF A MASTER SHEET IMAGES COMPRISING FROM ABOUT 0% TO ABOUT 40% BY WEIGHT OF A SOLID BINDER MATERIAL, FROM ABOUT 30% TO ABOUT 70% BY WEIGHT OF A SOLID UNDISSOLVED HECTOGRAPH DYESTUFF AND AT LEAST ABOUT 30% BY WEIGHT OF A SOLID HEAT-MELTABLE MATERIAL WHICH, IN ITS HEAT-MELTED STATE, IS A SOLVENT FOR THE SAID DYESTUFF; (B) HEATING SAID IMAGES TO A TEMPERATURE SUFFICIENTLY HIGH TO MELT SAID HEAT-MELTABLE MATERIAL BUT NOT SUFFICIENTLY HIGH TO MELT SAID SOLID BINDER, WHEREBY AT LEAST A PORTION OF SAID SOLID DYESTUFF IS DISSOLVED IN SAID HEAT-MELTED MATERIAL; AND (C) PRESSING SAID HEATED IMAGES AGAINST A COPY SHEET WHEREBY THE DISSOLVED DYESTUFF STAINS THE SURFACE OF THE COPY SHEET TO FORM DISSOLVED DYESTUFF IMAGES THEREON IN AREAS CORRESPONDING TO THE IMAGED AREAS OF THE MASTER SHEET. 